1. Field of the Invention
The present invention relates to a common mode choke coil array, and more particularly, to a two-element type common mode choke coil array having a structure in which two common mode choke coil elements including spiral coils are arranged side by side in plan view.
2. Description of the Related Art
A common mode choke coil array as described in Japanese Unexamined Patent Application Publication No. 8-138937 is an example of related art common mode choke coil arrays.
FIG. 11 illustrates the common mode choke coil array. A common mode choke coil (lamination type common mode choke coil) 50 is produced by alternately laminating insulating members and coil conductors, and integrally firing the laminated insulating members and coil conductors. Coils 40 and 41 and coils 42 and 43 are defined by electrically connecting the coil conductors, respectively. The coils 40 and 41 are paired, and the coils 42 and 43 are also paired. Thus, two common mode choke coils are formed. External electrodes 31a, 31b, 32a, 32b, 33a, 33b, 34a, and 34b are disposed at predetermined positions on the laminate body 50a so as to be electrically connected to both-ends of the coils 40, 41, 42, and 43, respectively.
Referring to the case where two coils are arranged side by side and adjacent to each other in plan view as in the lamination type common mode choke coil 50 (that is, the coils 40 and 42 are arranged side by side and adjacent to each other, as well as the coils 41 and 43), if the coils are desired to be arranged closely to each other, problems will be caused in that crosstalk generated between the adjacent coils (the internal conductors constituting the coils) becomes larger.
Accordingly, in the above-described lamination type common mode choke coil 50, one pair of the coils 40 and 41 is arranged to be sufficiently distant from the other pair of the coils 42 and 43 so that the adjacent coils exert no influences upon each other.
Thus, the lamination type common mode choke coil 50 has problems in that the respective coils are required to be arranged with a distance between them, so that the size of the choke coil 50 can not sufficiently reduced. If the respective coils are arranged closely to each other, the crosstalk between the adjacent coils will be increased.